# Circle of latitude

A circle of latitude or line of latitude on Earth is an abstract east–west small circle connecting all locations around Earth (ignoring elevation) at a given latitude coordinate line. Circles of latitude are often called parallels because they are parallel to each other; that is, planes that contain any of these circles never intersect each other. A location's position along a circle of latitude is given by its longitude. Circles of latitude are unlike circles of longitude, which are all great circles with the centre of Earth in the middle, as the circles of latitude get smaller as the distance from the Equator increases. Their length can be calculated by a common sine or cosine function. The 60th parallel north or south is half as long as the Equator (disregarding Earth's minor flattening by 0.335%). On the Mercator projection or on the Gall-Peters projection, a circle of latitude is perpendicular to all meridians. On the ellipsoid or on spherical projection, all circles of latitude are rhumb lines, except the Equator. The latitude of the circle is approximately the angle between the Equator and the circle, with the angle's vertex at Earth's centre. The Equator is at 0°, and the North Pole and South Pole are at 90° north and 90° south, respectively. The Equator is the longest circle of latitude and is the only circle of latitude which also is a great circle. As such, it is perpendicular to all meridians. There are 89 integral (whole degree) circles of latitude between the Equator and the poles in each hemisphere, but these can be divided into more precise measurements of latitude, and are often represented as a decimal degree (e.g. 34.637° N) or with minutes and seconds (e.g. 22°14'26" S). On a map, the circles of latitude may or may not be parallel, and their spacing may vary, depending on which projection is used to map the surface of the Earth onto a plane. On an equirectangular projection, centered on the equator, the circles of latitude are horizontal, parallel, and equally spaced. On other cylindrical and pseudocylindrical projections, the circles of latitude are horizontal and parallel, but may be spaced unevenly to give the map useful characteristics. For instance, on a Mercator projection the circles of latitude are more widely spaced near the poles to preserve local scales and shapes, while on a Gall–Peters projection the circles of latitude are spaced more closely near the poles so that comparisons of area will be accurate. On most non-cylindrical and non-pseudocylindrical projections, the circles of latitude are neither straight nor parallel. Arcs of circles of latitude are sometimes used as boundaries between countries or regions where distinctive natural borders are lacking (such as in deserts), or when an artificial border is drawn as a "line on a map", which was made in massive scale during the 1884 Berlin Conference, regarding huge parts of the African continent. North American nations and states have also mostly been created by straight lines, which are often parts of circles of latitudes. For instance, the northern border of Colorado is at 41° N while the southern border is at 37° N. Roughly half the length of border between the United States and Canada follows 49° N. (Wikipedia).

Determining where a point is on the unit circle

👉 Learn how to find the point on the unit circle given the angle of the point. A unit circle is a circle whose radius is 1. Given an angle in radians, to find the coordinate of points on the unit circle made by the given angle with the x-axis at the center of the unit circle, we plot the a

Quickly fill in the unit circle by understanding reference angles and quadrants

👉 Learn about the unit circle. A unit circle is a circle which radius is 1 and is centered at the origin in the cartesian coordinate system. To construct the unit circle we take note of the points where the unit circle intersects the x- and the y- axis. The points of intersection are (1, 0

From playlist Trigonometric Functions and The Unit Circle

Determine the point on the unit circle for an angle

👉 Learn how to find the point on the unit circle given the angle of the point. A unit circle is a circle whose radius is 1. Given an angle in radians, to find the coordinate of points on the unit circle made by the given angle with the x-axis at the center of the unit circle, we plot the a

Find the coordinate point of given the angle

👉 Learn how to find the point on the unit circle given the angle of the point. A unit circle is a circle whose radius is 1. Given an angle in radians, to find the coordinate of points on the unit circle made by the given angle with the x-axis at the center of the unit circle, we plot the a

Geometry of the Earth (1 of 3: Basic shapes & ideas)

More resources available at www.misterwootube.com

From playlist Working with Time

Coding Challenge #57: Mapping Earthquake Data

In this Coding Challenge, I visualize earthquake data from the USGS by mapping the latitude, longitude and the magnitude of earthquakes with p5.js. The map imagery is pulled from mapbox.js and the math demonstrated coverts latitude, longitude to x,y via Web Mercator. 💻Challenge: https://t

From playlist 10: Working with data - p5.js Tutorial

Geometry of the Earth (3 of 3: Measuring latitude & longitude)

More resources available at www.misterwootube.com

From playlist Working with Time

Area of a Sector, Angular Velocity, Applications (Precalculus - Trigonometry 5)

How to find the Area of a Sector, Arc Length on a great circle of a sphere, Angular Velocity, Rotational Velocity, and other applications. Support: https://www.patreon.com/ProfessorLeonard

From playlist Precalculus - College Algebra/Trigonometry

Python Maps with Folium

In this Python tutorial we will go over how to create maps with the folium package. folium jupyter notebook with examples: https://github.com/groundhogday321/python-folium folium jupyter notebook toggle marker groups: https://github.com/groundhogday321/python-folium-toggle-marker-groups

From playlist Data Visualization for Data Science

Learn how to find the point of the unit circle when given a specific angle

👉 Learn how to find the point on the unit circle given the angle of the point. A unit circle is a circle whose radius is 1. Given an angle in radians, to find the coordinate of points on the unit circle made by the given angle with the x-axis at the center of the unit circle, we plot the a

Earth Geometry Lesson 3 - Distance between two points on small circle

In this video we talk about how to calculate the distance between two points on the same small circle (latitude).

Teach Astronomy - Latitude and the Sun

http://www.teachastronomy.com/ The apparent position of the Sun in the sky depends on your position on the Earth's surface.  The regions between plus twenty-three and a half degrees Northern Latitude, the Tropic of Cancer, and minus twenty-three and a half degrees latitude, the Tropic of C

From playlist 02. Ancient Astronomy and Celestial Phenomena

Earth Geometry lesson 2 - Distance between two points on great circle

In this lesson we talk about how to find the distance between two points on the same great circle (i.e. same longitude, or two points on the equator).

Find the coordinate point of the given angle

👉 Learn how to find the point on the unit circle given the angle of the point. A unit circle is a circle whose radius is 1. Given an angle in radians, to find the coordinate of points on the unit circle made by the given angle with the x-axis at the center of the unit circle, we plot the a

Find the coordinate point of the given angle

👉 Learn how to find the point on the unit circle given the angle of the point. A unit circle is a circle whose radius is 1. Given an angle in radians, to find the coordinate of points on the unit circle made by the given angle with the x-axis at the center of the unit circle, we plot the a

Find the coordinate point of the given angle

👉 Learn how to find the point on the unit circle given the angle of the point. A unit circle is a circle whose radius is 1. Given an angle in radians, to find the coordinate of points on the unit circle made by the given angle with the x-axis at the center of the unit circle, we plot the a

Find the coordinate point of the given angle

👉 Learn how to find the point on the unit circle given the angle of the point. A unit circle is a circle whose radius is 1. Given an angle in radians, to find the coordinate of points on the unit circle made by the given angle with the x-axis at the center of the unit circle, we plot the a

Find the coordinate point of the given angle

👉 Learn how to find the point on the unit circle given the angle of the point. A unit circle is a circle whose radius is 1. Given an angle in radians, to find the coordinate of points on the unit circle made by the given angle with the x-axis at the center of the unit circle, we plot the a